SIM/Smart Card Level Translators

in µMAX

_______________________________________________________________________________________

9

est, which is then discharged into the test device

through a 1.5k

Ω resistor.

Applications Information

SIM/Smart Card Interface

To provide 5V when interfacing with a 5V SIM/smart

card, 3V systems require a DC-DC converter. The

MAX1686H +5V regulating charge pump for SIM cards

provides 0V/3V/5V for full compatibility with SIM/smart

card specifications. Figure 4 shows the charge pump

for SIM card applications. Alternatively, the MAX619

generates a regulated 5V from input voltages as low as

2V.

SPI/QSPI/MICROWIRE Interface

The MAX1740/MAX1741 are also useful as 3V/5V level

shifters in SPI, QSPI, and MICROWIRE applications

(Figure 5). On the slave side, connect CLK to SCLK,

RST to CS, and IO to DOUT and DIN. The unidirectional

level shifters transfer chip select and clock signals to

the slave device(s), while the bidirectional level shifter

transfers data.

CHARGE-CURRENT

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

Cs

100pF

1M

1500

Ω

HIGH-

VOLTAGE

DC

SOURCE

DEVICE

UNDER

TEST

Figure 3a. Human Body ESD Test Model

90%

36.8%

TIME

CURRENT WAVEFORM

PEAK-TO-PEAK RINGING

(NOT DRAWN TO SCALE)

Ir

10%

0

0

AMPERES

Figure 3b. Human Body Model Current Waveform

SIM OR

SMART

CARD

SYSTEM

CONTROLLER

CLK

RST

IO

GND

GND

IO

CLK

RST

OUT

GND

PGND

GND

+3.0V

3.0V OR 5.0V

MAX1740

MAX1741

MAX1686

MAX1686H

SHDN*

SHDN

3/5

OPTIONAL

RIN

IN

CXN

CXP

CIN

OPTIONAL

DATA

DDRV*

SHDN FOR MAX1740 ONLY

DDRV FOR MAX1741 ONLY

*

Figure 4. Using MAX1740/MAX1741 and MAX1686/MAX1686H

Charge Pump for SIM Card Applications

SPI/QSPI/

MICROWIRE

SYSTEM

SYSTEM

CONTROLLER

SCLK

CS

DOUT

DIN

GND

GND

IO

CLK

RST

OUT

SET

PGND

GND

+5.0V

+3.3V

MAX1740

MAX1741

MAX8867

MAX8860

SHDN*

SHDN

OPTIONAL

RIN

IN

CIN

OPTIONAL

DATA

DDRV*

SHDN FOR MAX1740 ONLY

DDRV FOR MAX1741 ONLY

*

Figure 5. MAX1740/MAX1741 with SPI/QSPI/MICROWIRE

Interfaces

TRANSISTOR COUNT: 114

___________________Chip Information